The word you yell when you are about to let loose a serious case of projectile diarrhea. Usually into the toilet or into the back of the toilet bowl (sometimes on the seat or completely out of the toilet as a whole).
Sometimes said like this: SHOT!... Guun!!!
(a quick "SHOT!" followed by a 1.5 second pause, then "Guun!!!")
When somebody sends a (usually generic) snapchat to multiple people at once, in the hopes it will spur popularity with them, begin convos with somebody, or keep a streak alive.
Also includes when somebody sends the same snapchat they've posted to their story to other people directly.